Can you name different implementations of the ExecutorService interface that you know?

In Java, the ExecutorService interface has several popular implementations provided through the Executors class:

• ThreadPoolExecutor — a basic thread pool implementation with flexible configurations.
• ScheduledThreadPoolExecutor — an extension of ThreadPoolExecutor for executing tasks with delay or periodically.
• ForkJoinPool — a specialized pool for tasks that can be broken down into subtasks (used in the Fork/Join Framework).

Examples of creation:

ExecutorService fixedPool = Executors.newFixedThreadPool(5);
ExecutorService cachedPool = Executors.newCachedThreadPool();
ExecutorService scheduledPool = Executors.newScheduledThreadPool(3);
ExecutorService forkJoinPool = new ForkJoinPool();

Each implementation is suitable for different scenarios: a fixed pool for a limited number of threads, a cached pool for dynamic thread creation, a scheduler for delayed tasks, and ForkJoinPool for parallel computations.